Function and body composition of patients with mitochondrial disease

Patients with mitochondrial disease (MD) experience, because of a disorder in
the intracellular energy generation, a variety of complaints such as muscle
pain, swallowing complaints, endurance intolerance. Treatment of these patients
is mainly supportive for remaining functionality and quality of life. Patients
with other neuromuscular diseases express a diminished physical functioning
with changes in body composition, e.g. decreased muscle mass and an increase in
fat mass. It is yet not known whether patients with mitochondrial disease
experience similar symptoms.
Our hypothesis is that patients with mitochondrial disease have changes in body
composition and that they have decreased physical function compared with
healthy control subjects. If this is the case, improvement of body composition
may be a goal of the treatment (dietary) intervention.

1. Determine body composition of MD patients;
2. Determine physical function of MD patients;
3. Determine the association of body composition and physical function of MD
patients.

An observational, cross-sectional study to determine the association between
body composition and physical function in MD patients as compared with matched
healthy controls (matched for age, gender and BMI). Physical function and body
composition will be measured once after an overnight fast. Nutritional intake
and nutritional status will be assessed, as these factors may influence body
composition as well as physical function. All parameters will be assessed
according to the usual care procedures for MD patients in the "Mitostraat"
(Radboud Centre for Mitochondrial Medicine). Parameters of the healthy controls
will be assessed identically at the Nutritional Assessment Lab at the HAN
University of Applied Sciences.

The risk is low. The measurements of body composition, physical function and
nutritional intake are part of usual care for large groups of patients and is
considered safe. The burden for healthy volunteers consists of one visit of
about two hours for measurements at the HAN, being fasted, the measurements
itself, registration of nutritional intake during three days in advance of the
visit and the DEXA scan. None of the measurements are invasive. Patients will
be measured in the hospital during their usual care before breakfast.

Advantages: individual questions on nutrition, body composition and physical
function may be answered by the investigator. Also, MD patients will receive
extra attention and information on their nutritional status and functioning.
Healthy controls will receive a report on their physical function, body
composition and nutritional status. In case of odd outcomes for healthy
controls may this will be noted in the report and the individual will, when
relevant, be referred to a physician.